The U.S. House of Representatives Thursday passed a bill on a mostly party-line vote to change an Obamacare rule classifying employees who work at least 30 hours as full time.

The 248-179 vote in favor of the “Save American Workers Act” included support from all six Republicans in the Alabama congressional delegation; Rep. Terri Sewell, D-Birmingham, voted “no.”

The Mississippi delegation was similarly split, with all three Republicans voting “yes.” and Democrat Bennie Thompson voting “no.”

The bill, which faces grim prospects in the Democratic-controlled Senate, would count workers as part time unless they work at least 40 hours a week. Supporters contend that the change would protect some 2.6 million jobs that are threatened by an Affordable Care Act requirement that companies provide insurance. Supporters argue that companies will respond to the law by reducing workers’ hours below 30 hours so that they will count has part-timers.

“Obamacare is striking at the very heart of the American economy, placing workers at risk of having hours cut and forcing small businesses to make tough choices on whether to limit growth to avoid expensive fines,” U.S. Rep. Bradley Byrne, R-Fairhope, said in a prepared statement. “This law threatens to create a new class of part-time workers forced to find two or more jobs just to get by. This doesn’t represent the promise of the American dream so many have risked their life to protect.”

The bill has support from an array of interest groups. The nonprofit organization maplight.org reports that organizations in favor of the law outspend labor unions and other opponents on campaign contributions by a 13-1 margin in 2011 and 2012. Most representatives from Alabama – Byrne is not included because he was not in Congress at the time – received contributions from the business groups.

Sewell is the only Alabama representative who took money from unions, but it was just $5,000, compared with $91,200 from groups in support of the legislation.

Opponents of the bill argued that it would hurt the workers it purports to protect. The nonpartisan Congressional Budget Office estimated that the law would strip up to 1 million Americans of health insurance between 2015 and 2024. Less than 500,000 would become uninsured, while the rest would find insurance through Medicaid, the Children’s Health Insurance Program or the Affordable Care Act insurance exchanges, according to the CBO projections.

The analysis also projects that the bill would increase the deficit by $73.7 billion over that 10-year period as a result of less money from fines against businesses not insuring their workers and because more people would end up receiving government assistance to obtain health care.

Rep. Martha Roby, R-Montgomery, wrote on her Facebook page that the bill passed Thursday would increase wage earners’ paychecks.

“Too many Americans are already struggling to make ends meet and Obamacare only makes it worse,” she wrote.

Byrne said in his statement that he has not given up hope of repealing Obamacare altogether.

“It is becoming clearer every day as the American people are forced off their existing coverage, subjected to skyrocketing premium costs, and prevented from keeping their doctor, that this law is a destructive force for families and workers across our country,” he stated. “I will keep fighting to ensure Obamacare is not allowed to hurt workers in Southwest Alabama.”